No, and how he felt would depend on how it was explained to him. Elliot does believe people have the right to take justice into their own hands if the law fails, but he is not a believer in revenge or anything like that, it has to actually be just and not over kill. Also he isn't a fan of execution, he believes people should pay for their wrongdoings by serving society, because the dead can't do shit other than not make things any worse, and the ideal is for people to work to pay back their wrongs.

SO IN SHORT HE PROBABLY WOULDN'T BE HAPPY AND HE WOULDN'T LET YOU GET AWAY WITH IT AGAIN and he expects you to be a good upstanding member of society in the future. But since he is aware that Yuri is just a good person it wouldn't horribly shake him or anything.

What's Yuri think of Lucifer?